The object of this research is to increase our understanding of the mechanism of RNA polymerase from E. coil by applying spectroscopic techniques such as circular dichroism, difference absorption and fluorescence spectroscopy. CD and difference spectroscopy will be used to study the conformation of isolated subunits and how these change upon forming the intact enzyme. The interaction of RNA polymerase with synthetic polynucleotides and with restriction fragments enriched with promoter sequences will be investigated. Fluorescent probes which are covalently or noncovalently attached to RNA polymerase will be investigated. Fluorescent probes which are covalently or noncovalently attached to RNA polymerase will be investigated. We will study the adenylation of the alpha chains of RNA polymerase, a modification which occurs in infection by bacteriophage T4. Photoaffinity labelling with 8-azido ATP and nitration of tryosyl residues are also being studied as probes of mechanisms.